Fix Python unit tests
diff --git a/setup.py b/setup.py
index 135c818..01faa4c 100644
--- a/setup.py
+++ b/setup.py
@@ -232,6 +232,7 @@
     'setup_requires': SETUP_REQUIRES,
     'cmdclass': COMMAND_CLASS,
     'tests_require': TESTS_REQUIRE,
+    'test_suite': TEST_SUITE,
     'test_loader': TEST_LOADER,
     'test_runner': TEST_RUNNER,
 }